Business Process Optimization

I am going to work on Business Process Optimization Project, which i haven't done before. its like a research for my future BPO projects..

In this project we have more than 400 business processes (in ARIS) as input, our expected output is optimized, efficient processes which lead to reduction in number of approvals and reduction in efforts (man hours). Reduction in Man hours is primary objective by making processes more efficient.

can any one help me for

1. creating road map for this project

2. how ARIS can help me for that

3. How KPI effects the business processes? how i can use KPI for optimizing the processes

4. is there any standard approach available for business process optimization.